Denver — Colorado U.S. Senators Michael Bennet and John Hickenlooper and Colorado U.S. Representative Joe Neguse called on U.S. Department of the Interior (DOI) Secretary Doug Burgum and U.S. Department of Agriculture (USDA) Secretary Brooke Rollins to address invasive zebra mussels in the Colorado River after the river was officially declared positive for mussels in July.
In their letter, the lawmakers requested an update on the implementation of the Expanding Public Lands Outdoor Recreation Experiences (EXPLORE) Act, enacted last year, which includes a provision that authorizes DOI and USDA to improve how they monitor and respond to aquatic invasive species.
“More than 40 million people across seven states rely on the Colorado River Basin, and the spread of these invasive species into this critical body of water could have devastating impacts for many communities across the West,” wrote Bennet, Hickenlooper, and Neguse. “We understand the many pressures on your agencies, but request that you prioritize the implementation of these provisions in light of the threat facing our waterways and rivers in the West.”
Zebra mussels, which were first detected in Colorado in 2022, are an invasive species that poses a significant threat to Western rivers and reservoirs. Once established, these intruders are nearly impossible to eradicate and wreak havoc on crucial water infrastructure, limit recreation opportunities, and harm ecosystems and local economies.
Bennet has fought to safeguard the Colorado River from invasive species since 2010. He secured provisions in the 2018 Water Resources Development Act (WRDA) and the 2022 WRDA to protect Colorado’s watersheds from invasive species through the use of watercraft inspection stations. In July 2023, Bennet reintroduced the Stop the Spread of Invasive Mussels Act, legislation to slow the movement of aquatic invasive species, like zebra and quagga mussels, into Western States. In December 2024, Bennet and Neguse celebrated the unanimous House and Senate passage of the Stop the Spread of Invasive Mussels Act, which was later incorporated into the EXPLORE Act.
The text of the letter is available HERE and below.
Dear Secretary Burgum and Secretary Rollins,
We write to request an update on the implementation of the Expanding Public Lands Outdoor Recreation Experiences (EXPLORE) Act, Public Law 118-234. In light of recent news that invasive zebra mussels have been found in the Colorado River and in other waterways in Western Colorado, we specifically request an update on your efforts to implement Section 128: Aquatic Resource Activities Assistance.
Invasive zebra mussels reproduce and spread quickly, often attaching to watercraft and moving quickly through different bodies of water. Zebra mussels are particularly dangerous for water infrastructure, as they can attach to, clog, or block water storage, treatment, and distribution systems–potentially causing millions of dollars of damage. Without natural predators, the mussels also damage ecosystems, which has led to the loss of larger fish in the Great Lakes and resultant declines in outdoor recreation and impacts to local economies.
Zebra mussels have recently been discovered in the Colorado River and other bodies of water along Colorado’s Western Slope, including Eagle County and outside of Grand Junction. More than 40 million people across seven states rely on the Colorado River Basin, and the spread of these invasive species into this critical body of water could have devastating impacts for many communities across the West.
The EXPLORE Act was signed into law in the 118th Congress, which included additional authorities for the Department of Interior (DOI) and U.S. Department of Agriculture (USDA) to respond to and monitor aquatic invasive species, including zebra mussels, and established a Vessel Inspection and Decontamination Station grant program for Reclamation States in Section 128: Aquatic Resource Activities Assistance. We understand the many pressures on your agencies, but request that you prioritize the implementation of these provisions in light of the threat facing our waterways and rivers in the West.
We request responses to the following questions by August 29, 2025:
- What is the status of implementation of Section 128 of Public Law 118-234, including the status of the Grant Program for Reclamation States outlined in Section 128 (c)? When do you anticipate fully implementing the authorities provided within Section 128?
- What actions have DOI and USDA taken to combat the spread of quagga and zebra mussels throughout our nation’s waterways?
- What agency resources have been allocated to address the threat of invasive mussels by DOI and USDA?
- Have DOI and USDA offered assistance to the State of Colorado to combat the spread of the invasive mussels?
Thank you for your prompt attention to this matter.